(The word of the day is taken from the Torre Bueno Glossary of Entomology)

Fecifork, in certain larval Coleoptera and Lepidoptera, anal comb.

This is one I had never heard of before! It seems to be another awesome and useful word which doesn’t actually get used very often.

We like to talk about anal combs here in the lab, because many caterpillars use them to fling their frass. I have a longer post about frass and frass flinging here.

This definition also covers a body part used by beetle larvae. They do not use their fecifork to fling their frass, but instead to hold it over their body as a sort of “please don’t eat me because I’m covered in poop” shield. Some species also collect their skins from past molts. Tortoise beetles (family Chrysomelidae, subfamily Cassidinae) are especially well known for this. A browse through Bugguide reveals many photos of beetle larvae adorably adorning themselves with their own frass. As you can see in the images below, they can use the fecifork to cover or uncover themselves. Click this link to see even more!